class Point {
	private int x;
	private int y;

	Point(int x, int y) {
		this.x = x;
		this.y = y;
	}
}

class Circle {
	Point center;
	double r;

	Circle(Point p, double r) {
		center = p;
		this.r = r;
	}

	double area() {
		return Math.PI * r * r;
	}

	static double area(double r) {
		return Math.PI * r * r;
	}

	static double area(Circle c) {
		return Math.PI * c.r * c.r;
	}
}

class Main {
	public static void main(String[] args) {
		Circle c = new Circle(new Point(1, 1), 2);
		System.out.println(c.area());

		System.out.println(Circle.area(2));

		System.out.println(Circle.area(new Circle(new Point(1, 1), 2)));
		
		
		
	}
}
